Gemasolar a thermal solar power plant with 15 hours, Ignacio Burgaleta (Torresol Energy)

11 June 2013, Madrid © Torresol Energy

GEMASOLAR: A THERMAL SOLAR POWER PLANT WITH

15 HOURS OF THERMAL STORAGE SYSTEM

WORKSHOP ON APPLICATIONS OF SOLAR FORECASTING

Juan Ignacio Burgaleta

Director of Technology

© Torresol Energy 2 11 June 2013, Madrid

GEMASOLAR: A THERMAL SOLAR POWER PLANT

WITH 15 HOURS OF THERMAL STORAGE SYSTEM

INDEX

1. Torresol Energy

2. The GEMASOLAR Plant

3. Innovations

4. Operation

5. Construction

6. Commercial operation

7. Conclusions




1. Torresol Energy

• Engineering, consulting, and systems inte-

gration company. Founded in 1956.

• Very active in Solar Energy since 2000. – Technology developer: SENERtrough collector system, Sensol

software, heliostats, heliostat axis drive mechanisms, molten salt

technology (as storage system and as heat transfer fluid) central

tower receiver… amongst many other innovations.

– PSA Tower Prototype

– Turn Key Projects: Andasol 1 & 2, in Granada; Extresol 1, 2

& 3, in Badajoz; one plant in La Garrovilla (Badajoz); one

plant in Alvarado (Badajoz); and two plants in Navalvillar de

Pela (Badajoz).

60% 40%

• 100% “Mubadala Development

Company” stockholding.

• Mubadala Development Company”

belongs to the Abu Dhabi Emirate.

• Goal: development and commer-

cialization of innovative technologies

in renewable, alternative and sus-

tainable energies.

A STRONG ALLIANCE




1. Torresol Energy

GEMASOLAR

(Tower)

VALLE 1

(PTC)

VALLE 2

(PTC)









• Storage system

Solar energy Solar field and

central tower receiver Molten salts

storage system

• Generation system

Molten salts

storage system

Steam

generation

system

Turbine/generator

system Grid





• High thermal storage capacity (24 hours).

• The same fluid is used for heat transfer and storage.

• The molten salts reach highest temperatures (565ºc) maximizing thermodynamic efficiency.

• The whole piping system is contained in an small area, reducing the heat losses, the

maintenance costs and minimizing the possibility of leaks.

• Lower operation risk (No mobile piping system. No swivel joints. No thermal oil).

• Highest cycle efficiency.

Advantages of Central Tower with Molten Salt Technology








3. Innovations (Heliostats)

• High surface (115 m2).

• High optic quality and precision.

• Integrated facet mirror-structure.

• Innovative system of facets union.

• Reduced manufacturing, assembly and

maintenance costs.

Developed by SENER




3. Innovations (Receiver)

• Optimize size to minimize thermal losses.

• High flow of incident radiation.

• Optimize the design to the maximum temperature

of the metal.

• Thermal maximum efficiency.

• Designed for 25 years of operation.

Solar receiver

Prototype receiver testing in

the PSA of Almería

Receiver Developed by SENER with

PSA-CIEMAT colaboration




3. Innovations

Solar Field Control System

• Innovative Control system of solar

field composed by 2650 heliostats,

positioned at north, south, east and

west of the tower.

• Optimize the electricity consumption

of the heliostat actuation system.

• Development of a new pointing

strategy that guarantees the good

distribution of the solar flow incident

in the receiver.

• Reduce the time of heliostats de-

focusing. Developed by SENER




3. Innovations

Molten Salt Storage System

– Tranference fluid and thermal

storage: Nitate molten salts 60%

Na NO3 y 40% KNO3.

– 15 hours of thermal storage

capacity, operating with turbine in

nominal conditions.

– Operatoin tempeature 565.

– Pumping of salts to the receiver

placed in the tower at 140 m.

Power block, molten salt storage system of

the GEMASOLAR Plant

Developed by SENER




4. Operation

GEMASOLAR Flow Diagram




4. Operation

GEMASOLAR Daytime Operation




4. Operation

GEMASOLAR Daytime Operation during Cloudy Periods




GEMASOLAR Nightime Operation

4. Operation




5. Construction

Aerial view of the GEMASOLAR Power Block




5. Construction




5. Construction

Aerial view of the GEMASOLAR Plant




6. Commercial Operation





• Commissioning activities started November 2010:

− Heliostats calibration.

− Salt molten in a temporary installation and stored in the cold tank (November –

December 2010)

• End of April 2011 plant synchronized.

Start up and Commissioning




• From early May 2011 providing electricity to the grid.

• End June, 24 hours of uninterrupted electricity production.

• On July 6 2011 performance test, result exceeded theoretical prediction.

• Excellent hourly production predictions.






Starting & Shutting Down the Receiver

• Every day the receiver temperature changes quickly from the environmental conditions till

operation conditions (565ºC)

• Procedures to control all the parameters-components which affect the receiver filling and

drainage developed by Torresol Energy to secure the efficiency and the security (delicate

operation)

• Complex system: Sincronization between Solard Field (heliostats) and the Central

Receiver System (CRS)

• Thermography cameras are part of the control tool for the radiation flow onto the receiver

and are synchronized with the solar field software (heliostats pointing)





Starting & Shutting Down the Receiver

• Importance of a good reciever drainage

• The molten salt must be between 260ºC and 565ºC.

• Operational improvements extend the daily

production

• Calibration of the heliostats: Targets located below

the receiver to calibrate the heliostats




Actual Guarantee

– Receiver Thermal Power 135 MWTh 120 MWTh

– Net Electrical Production 414.3 MWh 302 MWh

– Receiver Outlet Salts Temp. 565 ºC 565 ºC

– Gross Power 19.9 MW 19.9 MW

– Net Power 17.0 MW 17.0 MW

24 h Overall Performance Test passed on July 6th, 2011






Production dates. From 16-08-2011, 00:00 hour to 17-08-2011, 00:00 hour





Non-stop operation in Winter time





Turbine continuously running at nominal power in summer




12 DAYS OF CONTINUOUS PRODUCTION





7. Next Steps

• We, and most of the analysts, consider that the

technology of Central Tower Plants with Molten Salts

has higher opportunities to achieve the grid parity in

a shorter period of time due to:

− Larger future cost reduction.

− Size to be increased.

− New equipment yet to be developed.

− Affordable construction materials.

• Next Tower Plant with Molten Salt Storage System:

− + 500 MWt receiver ( +12.000 heliostats)

− Storage System capacity depending on Market

requirements




7. Conclusions

• GEMASOLAR is the first commercial-scale plant featuring a central tower

molten salt receiver with thermal storage capabilities supplying electricity

to the grid from May 2011.

• The molten salt thermal storage system helps avoid fluctuations in power

supply and enables to produce electricity during 15 hours in the absence

of solar radiation.

• The 19.9 MWe GEMASOLAR Plant became the first CSP ever to

generate uninterrupted electricity for 24 hour at full capacity.

• Next Tower Plant and Molten Salt System with increased power

11 June 2013, Madrid © Torresol Energy

Thank you